Digital Light & Color

Using the Freehand Outline tool in the Mask does not enable the Undo command, other mask tool has to be used.
Also, using Undo after Freehand Outline undoes more then the only last masking step, even those made with a different masking tool. I guess it is one step (made with whatever masking tool) before Freehand Outline step and all the following Freehand Outline steps made after. Once another masking tool is used, Undo is "undoing" as expected.

I hope the descrition it is not too much confusing.

PWP7.0.5-32bit ...

I too will experience this with the Mask Tool 'Undo'...

(1) the Mask Tool - Undo is 'inactive' when opened to apply a mask to an image in the work space.
(2) the Mask Tool - Undo will act as 'None' when:
...a. lower-left Apply Add a mask image to an image in the work space
...b. make any other change to the applied mask... ...subtract a mask area for instance
...c. clicking Undo will remove all of the applied mask, not just b.

...den...
Vista 32 Home Premium, SP2, latest version/updates
AMD Athlon 64 x2 6000+ processor
3 GB DDR2 dual channel RAM
2 MB ReadyBoost Cache
500GB hard drive with 100GB free space

This has been fixed for the next beta release.